The government of Sri Lanka and Tamil Tiger rebels wrapped up their sixth round of peace talks in Japan with no progress on political issues. But they renewed their commitment to the 13-month cease-fire, amid news of a deadly sea clash involving suspected rebels.

Sri Lanka's peace negotiators said Friday that the government and Tamil Tiger rebels would continue to move forward with efforts to resolve one of Asia's longest civil wars. But no concrete progress was made on how to share political and economic power under a federal system, a key concept agreed to at talks last year and the basis for a final settlement.

They also did not finish work on humanitarian concerns, but said they plan to issue a human rights declaration at their 7th round of talks next month in Thailand.

Paikiasothy Saravanamuttu, the executive director of a Colombo think tank, called the Centre for Policy Alternatives, said that despite the shortcomings, the talks should be viewed in a positive light. "The challenge at the present moment is to implement the agreements made and to consolidate whatever gains have been arrived at," he said. "I think, in that sense, what we are going to see in the future is that each round of talks will not yield a major agreement, but is rather doing the more unspectacular work of implementing consolidating what has been arrived at."

Mr. Saravanamuttu also expressed concern that the U.S.-led war with Iraq could eclipse peace efforts in Sri Lanka, which a Japanese envoy to the talks called "the only bright spark in a turbulent period the rest of the world is going through."

Japan will host an international donors conference for Sri Lanka in June, which is expected to raise millions of dollars to rebuild the nation after 19 years of war, which killed more than 60,000 people.

The two sides ended their four-day talks in the Japanese resort town of Hakone with news of a deadly sea clash. Sri Lankan naval officials say a group of rebels attacked a Chinese fishing trawler off the east coast of the island nation and killed more than a dozen crew.

Negotiators at the talks in Japan would not comment on the incident, saying they needed time to confirm the facts.